MOODY AIR FORCE BASE, Ga. (AFNEWS) --
Members of the 23rd Civil Engineer Squadron are using a new propane-air mix system to create an alternative source of fuel, allowing the base to avoid paying high contract fees for natural gas.
The system, which Moody AFB officials began using in November, substitutes propane for the natural gas used on base at times when the utility company charges higher rates, said Bill Cordes, a 23rd CES liquid distribution system mechanic.
"We heat the liquid propane until it boils into a gas, then dilute it with air to the correct ratio," said Mr. Cordes. "One cubic foot of liquid propane makes about 270 cubic feet of gaseous propane.
"But this pure gas is too rich to burn; it needs the right amount of oxygen to burn correctly in the boilers," he said. "The plant mixes pure propane with roughly 90 percent air to create the proper specific gravity to match the natural gas it is replacing."
Converting liquid to gas isn't necessarily difficult or complicated, Mr. Cordes said.
"The important improvement is with the automated precision we now have for mixing pure gas with air at the high demands of the base," he said. "Too 'dry' of a mixture and we could flame out the stoves, boilers and hot water heaters all over the base. If the mix is too 'wet' we could ruin them."
The $864,500 facility uses a sophisticated computer system to monitor the heaters, pressure sensors and all of its valves. It then displays every measurement on a single touch-screen display. The entire system can also be remotely monitored through an Internet connection.
The new air-mixing plant uses two systems, said Don Montgomery, the 23rd CES maintenance engineering section chief. Each "loop" is able to produce enough usable gas to supply the peak needs of the base. In case of a single system failure, redundancy will ensure the base does not lose gas service.
"We now have an alternate energy source when the gas company goes into high-demand rates," Mr. Montgomery said. "Instead of paying prices of $30 per thousand cubic feet of natural gas, we can now produce our own "natural gas" from our propane storage for $15 per thousand cubic feet."
"Our gas supplier charged us a demand fee of $3,282 per month to have uninterrupted service," said Mr. Montgomery. "In addition we also had to pay large amounts for pipeline pass-through charges and transportation fees. In the end, Moody AFB officials paid $7,850 a month in contract charges before we even used a single cubic foot of gas. Without these contract fees, Moody AFB will save $95,000 a year."
With these savings, the new propane mix plant should pay for itself in about eight years, Mr. Montgomery said.
The plant is supplied by two 30,000-gallon supply tanks, which is enough propane to fuel the base for 10 days "off the grid" without re-supply at the highest winter consumption rates, said Mr. Montgomery.
This also allows the base to change the terms of its natural gas contract and switch from an uninterrupted plan to an interruptible one.
In addition to spending less on gas, base civil engineers have also been looking at ways to consume less of it. The 23rd CES staff recently completed installation of efficient infrared radiant heaters into two large aircraft maintenance hangers. These systems replaced very inefficient low-pressure steam boilers, Mr. Montgomery said.
Other energy conservation improvements include the base-wide installation of energy monitoring and control systems. These upgrades have clearly been paying off for Moody AFB, Mr. Montgomery said.
"With all of our efficiency efforts combined, the base needed 2 million fewer cubic feet of gas this January than it used the previous year," he said.
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